Pathophysiology, Vascular syndromes, & Sequelae of CVA

Pathophysiology: cellular level is a Lack of blood flow→ oxygen/glucose deprivation→

neurons die w/in minutes in core tissue

Cell Survival depends largely on

severity & duration of ischemia

20-25% of blood flow is required for cells to survive

Lack of reperfusion (blockage lasting longer)

Neuronal activity stops→

infarct will expand

Ischemia triggers ischemic cascade→ leads to metabolic changes→ further damage to brain cells

Pathophysiology: ischemic stroke - Cerebral Edema due to

tissue necrosis, widespread rupture of cell membranes→ fluid moves into brain tissue

Most frequent cause of death in acute stroke

Characteristic of large infarcts of the MCA (supplies lots of brain) & ICA (supplies MCA)

Pathophysiology: ischemic stroke - consequences

Increased ICP

Intracranial HTN

Shifts of brain structures due to swelling

Pathophysiology: ischemic stroke Clinical Signs of Cerebral Edema includes decreased

consciousness, increased HR, irregular respiration, vomiting, unreactive pupils & papilledema, widened pulse pressure

Which management category of stroke has temporary interruption of BF?

sxs→ minutes to hours, no longer than 24 hrs

Increases risk for CVA and MI

Transient Ischemic Attack (TIA)

Which management category of stroke has stable, usually severe impairments?

major stroke

Which management category of stroke has neuro status declines following admission→ due to systemic or cerebral changes

Deteriorating stroke

Which management category of stroke for someone less than 45 yrs old?

young stroke

what are some determinants of severity & symptoms of CVA?

Location of lesion

Size of lesion

Nature of the lesion

Body structures involved

Availability of collateral BF

what vascular syndrome has contralateral hemiparesis & sensory loss (LE > UE)

Urinary incontinence

Apraxia

(medial aspect of cerebral hemisphere affecting LE homunculus)

Anterior Cerebral Artery Syndrome

what vascular syndrome has contralateral hemiparesis & sensory loss (UE > LE)

Left hemisphere lesion→ aphasia (language/communication)

Right hemisphere lesion→ Perceptual deficits

Homonymous hemianopsia (visual field cut on same side)

**Most common site of occlusion!!!

Middle Cerebral Artery Syndrome

what vascular syndrome has contralateral sensory loss (thalamic branches)

Homonymous hemianopsia, visual agnosia (can’t figure out what common objects are), cortical blindness if bilateral (occipital branches, loss of vision but respond to light)

Amnesia (temporal branches)

Posterior Cerebral Artery Syndrome

what vascular syndrome has massive infarction to areas supplied by the MCA?

Can lead to infarction of ACA territory if collateral BF isn’t present thru Circle of Willis

Significant edema possible→ herniation, coma, death

Internal Carotid Artery Syndrome

proximal MCA most significant damage due to

cerebral edema, LOC, brain herniation, death

what vascular syndrome is strongly associated w/ hypertensive hemorrhage & diabetic microvascular disease?

Caused by small vessel disease deep in cerebral white matter

Presenting sxs dependent upon impacted structures

Lacunar Stroke

what vascular syndrome has many can occur due to small vessel disease→ can be small & discrete

Larger infarcts→ very dangerous w/ high rate of mortality or multisystem dysfunction (supplier of posterior circulation/brain stem)

LOC, hemiparesis, disordered consciousness, vertigo, nystagmus, dysphagia, dysarthria, syncope, ataxia

Vertebrobasilar Artery Syndrome

what are the Neurologic sequelae (consequences) of stroke?

altered consciousness (lethargic, obtunded, stupor, coma)

aphasia

what type of aphasia where speech flows smoothly but auditory comprehension is impaired?

Fluent (Wernicke’s/Receptive)

what type of aphasia where comprehension is good, but speech production is labored or completely lost?

Non-fluent (Broca’s/Expressive)

what type of aphasia where severe presentation w/ impairments in comprehension & production of language?

global aphasia

what consequence of stroke that is a motor speech disorder causing slurred speech→ difficulty figuring out language plan?

Can occur due to lesions in primary motor cortex, primary sensory cortex, or cerebellum

dysarthria

what consequence of stroke is inability to swallow or difficulty swallowing?

dysphagia

what are some language & swallowing considerations following a stroke?

Must establish reliable communication

MUST follow lead of SLP for food/liquid (aspiration)

what is continued repetition of words, thoughts, or acts not related to current context?

perseveration

what pillar of cognition involves engagement in purposeful behavior?

executive function

changes in affect are emotional changes one might experience often due to lesions of the

frontal lobe, hypothalamus or limbic system can lead to emotional changes

what is emotional lability or dysregulation? uncontrollable laughter, crying

Pseudobulbar affect

what side hemisphere stroke involves:

Cautious, anxious, disorganized, frustration

Hesitant to try new things, benefits from support and feedback

Difficulty w/ communication, information processing (aphasia)

Realistic appraisal of current limitations

left hemisphere stroke

what side hemisphere stroke involves:

Difficulty w/ spatial/perceptual tasks

Quick, impulsive, poor insight/judgment/safety

Overestimates ability, unaware of deficits

Often will need frequent feedback to slow down & think things thru

decreased attention, awareness, memory, emotional

right hemisphere stroke

what perception issue following stroke is a complete unawareness on 1 side of body, environment, space?

Unilateral neglect/inattention

what perception disorders of spatial following stroke has hard time distinguishing separation from its background

figure ground

2 objects Disorders of spatial relations

form 

what type of disorders of spatial relations has difficulty understanding & remembering relationships between one location to another?

topographical

difficulty recongnizing no speech soudns or discriminating between them

auditory agnosia

inability to recognized forms or figures by handling them?

tactile agnosia (different mechanism from stereognosis) impairment in parietal lobe not DCML

what are more common acutely & more common in hemorrhagic CVA?

Can be life threatening; will require medical/pharm mgmt

seizures

other neurologic sequalae (consequences) of stroke

Bowel/Bladder Function: Very common→ toileting schedules are important

cardio-pulm function: Can inhibit rehab potential→ important to carefully monitor & prescribe exercise! Increased fatigue/decreased endurance

DVT/Pulmonary Embolism: Risk for DVT is high in acute phase. Often managed prophylactically w/ anticoagulants

Osteoporosis/Fracture Risk: Decreased activity/WBing. Increased risk for falls